This study investigated the disciplinary knowledge and nature of expertise among political science experts studying American political science. A comparison group of students who had completed an introductory undergraduate course in American political science also participated in the study. Numerous research studies have found that civics and government courses often focus on the transmission of information from textbooks and teachers to students. The result of this type of teaching, at least according to the measures we currently utilize, has been the failure of the majority of students to learn about American government, become invested in our system of government, and indicate their desire to participate in the future. Civic and educational leaders have called for the development of curriculum to promote critical thinking and improve student learning and participation. Yet, there is no research base for understanding what critical thinking looks like in civics and government and its related discipline of political science or what activities and methods will lead to increased student achievement. With history education as a model, where defining the discipline has led to a better understanding of critical thinking in history and a more robust approach to teaching, the author investigated what expertise in this subfield of political science looks like, how experts conceptualize the discipline, and what cognitive processes they use in their work using a concept sorting and mapping task, two problem-solving tasks, and an open-ended interview. Experts defined political science as an empirical discipline focused on phenomena related to government, power, and the allocation of resources. Experts also recognized relationships and connections between concepts in the discipline and used a variety of conceptual knowledge and strategic processing when engaging in their work, including recognition of context, the identification of sub-problems and constraints, and an acknowledgement of what they did not know. A comparison to the students allowed for the description of different levels of expertise. Implications of the study include the need for additional research on the strategic processing of political science experts and the potential to define educational outcomes for teaching and learning in civics and government classes.